Physical Layer

[PlAwAnSaI]

• Describe the role of bits in representing a frames

Type of Physical:

• Wireline
  • LAN (UTP, STP)
  • Cable modem coaxial
  • Fiber Optic cable (OFC)
• Wireless
  • AP

UTP cable:

• CAT5
• CAT6
  
• Straight through
• Crossover

UTP pros & consros:

• Easy to use and easy to cut
• Cheap

Cons:

• Length limit
• Size of cable
• Speed

en.wikipedia.org/wiki/Structured_cabling
Coaxial cable:

• Coaxial cable
• Coaxial splitter
• Cable modem (DOCSIS 2,3)

Fiber Optic cable:รู้จักชนิดของหัว Connector และชื่อเรียกอุปกรณ์ต่างๆ

• Single mode:
  • only 1 stream
  • far
• Multi mode:
  • many streams/wavelength
  • short
• LC
• FC
• SC

SFP Type and Length:

• Single mode SFP
• Multi mode SFP
• SFP UTP
• Single mode SFP+
• XFP 10G
• CFP 100G

Checker equipment:

• Power meter
• Red Source / Red Light / Light Source
• Traffic Checker

OFC Pros and Consros:

• High Speed
• Long Length Limit
• Small size cable (easy to wiring)

Cos:

• Expensive
• Difficult to cut
• Cracked make signal loss

DWDM:

• Router - ODF - DWDM - ODF - Router
• Long Length more than 80km

Dark Fiber:

• Router - (ODF - ODF) - Router
• Length depend on SFP

Optical Distribution Frames (ODF):

• Easy to manage cables
  
• ODF Box 144 core may standard in Telco
• ODF core label

Wiring Guide:

• Wire way fiber optic
• Wire way fiber optic and UTP
• Wire way under raise floor

Wiring step:

1. choose fiber length appropriately.
2. mark fiber optic both side with pen or sticker.
3. wiring fiber optic on wire way (upper or under).
4. make real label both side of cable.
5. check over cable after wiring. (cable tie)
6. check all of fiber optics with power meter.
7. call site controller to cross check again.

Power:

• Power Type (AC DC)
• Power consumption
• Heat
• Breaker size:
  • Main breaker
  • Sub breaker
• Power cable:
  • cross section area (Sqm)
  • color of cable
• AC power strip
• PDU/PDB
  
  

Wireless standard:

How to know cable length and cable type before wiring?

• Site survey
• Ask site controller
• If urgent, should prepare many as you can

How to check quality of fiber optic or UTP cable?Fiber optic:

• Use power meter.
• Check ping on router. No loss found.
• Check CRC error on router.
• Loop check, ensure SFP is usable.
• Cut hop test, ensure connector isn't broken.

How to expansion WAN link step by step?

• Request DWDM from transmission team.
• Wiring fiber optic.
• Check power (dBm).
• Ensure no routing configuration of IPs will configure
• Configure IP WAN to ping test. (ensure IPs don't duplicate on the existing network).
• Check CRC error.
• Configure routing and other configuration.
• Monitor after expansion.

How to find cable on ODF when change or remove cable?

• Verify label on cable first. Both direction must have same label detail.
• Verify description on configuration.
• Cross check with DWDM document.
• Unplug cable on line card first and check status on link.

How make port status change to "UP"?

• Power of fiber optic in between recommend parameter.
• Negotiate

Tip and trick check DWDM:

• After finished wiring physical to DWDM, call to DWDM team to check power on each side.
• Inform information of DWDM link number.

Tip and Trick to check broken SFP, broken cable:

• Loop test TX, RX on 1 SFP.
• Use Power meter.
• If power high, use attenuation to reduce power.

Tip and Trick to contract site controller smoothly:

• Always use polite speech.
• When go to site, buy some gift. Work will be easier.
• If use telephone, use opposite gender will talk easier.

Cr: Meng@TRUE

Mobile:

• Un-license
  • 2.4 GHz: Less channel but far
  • 5 GHz
• License

Cr: P'Top@TRUE